DE202007001771U1 - Wood hollow box carrier structure, e.g. for walls and ceilings, has upper and lower multi-layer boards separated by vertical struts at the ends and intermediate block board struts to form the hollow boxes - Google Patents

Abstract

The hollow box carrier structure, for walls and ceilings and the like, has upper (1) and lower (2) multi-layer boards each with at least two layers (1.1,1.2,2.1,2.2), using solid wood. Vertical struts (3.1,3.2) are between the boards of thick coniferous planks and/or block boards with wide block layers (4.1,4.3). The hollow boxes (9) are surrounded by insulation layers (5). The structure is bonded together by a formaldehyde-free adhesive or vacuum pressing.

Description

The The invention relates to a wooden box girder, especially for larger spans.

Draw hollow box girders characterized by the fact that they are significantly lighter than solid sections, their bending capacity with the same external dimensions and the same material opposite a solid cross-section in proportion hardly any material savings and significantly less building material need becomes.

Hollow box sections made of wood are usually glued at the joints. For smaller spans and stresses can also nail connections for execution come. The latter, however, find because of the relatively high workload and the associated costs barely apply.

A box girder made of wood and wood materials is from the DE 199 57 080 A1 known. According to this doctrine square chisels are applied as straps on a large format plate. Insulating material is inserted between these square blocks. Subsequently, a second large-format plate is covered over it. The connection of the plates and woods is done here either by nailing or by gluing. Slitters separate the connected elements into single box girders.

such Wooden components are intended for the construction of wall, ceiling and roof components in thermally insulated constructions find application in housing. This moves you in the usual spans from 3-8 m.

For larger spans were in Germany until the end of the 70s hollow box carrier with Upper belt and lower belt made of solid wood and arranged laterally Fighting wall sheets used. dimensions of 20/20 cm for Upper and lower belt and Kämpfstegplatten of 300 cm as a bridge height are quite common for larger spans, this type was displaced by the glulam beam (BS wood). It consists of at least three fiber-parallel glued together technically dried boards or board slats. The carrying capacity BS wood is up to 80% higher than at usual Lumber. Add to that the possibility the BS wood curved in almost any arch shape or in the direction of Twisted longitudinal axis can be made so that an adaptation to the spatial structure of the building can (inter alia LKG - engineering office for building technology - Wiesbaden - www.elkage.de/index.html).

Such a composite wooden component is in the DE 20 2004 011 810 U1 described. In this timber structural element crosswise extending interconnected wood layers are used with respect to the wood-fiber direction.

task The invention is the sustainability of hollow box profiles to increase and so an alternative to the shown development towards BS wood to accomplish.

Is solved This object with the features of claim 1, advantageous embodiments Subject of the dependent claims.

Of the hollow box carrier according to the invention consists from a plate-shaped Layered top strap made of at least two solid wood panels, a plate-shaped Underlay in layer construction of at least two layers Solid wood and arranged between upper and lower flange in the carrier longitudinal direction extending and connecting upper and lower flange webs, wherein the Webs made of softwood boards and / or glulam (BS wood), each one web the hollow box carrier each bounded outside and between these webs at least one further web in the carrier longitudinal direction is arranged and touching or contiguous parts glued together.

there consist of the sandwich panels of upper and lower flange in a preferred execution from board layers of cross-and-board boards Boards longitudinal layers.

With the thus constructed wooden box carrier, at the bonding more touching or more abutting Parts by vacuum pressing using a formaldehyde-free Adhesive is done, the disadvantages of previous products such as high material usage and unfavorable Vibration behavior at large Spans overcome.

Of the proposed box girder is expandable. Through changes in the web arrangement and web geometry (e.g., conical lands, double T lands or other shapes) can optimize stress conditions. It exists the possibility, in the hollow box heat insulating materials and / or layers that have the mechanical properties continue to optimize. Furthermore, outside can be tissue and wear layers arrange, which improve the fire protection properties significantly. Through openings into the respective hollow box, especially in combination with the installation of insulation Sound-absorbing measures can also be comparatively simple realize. This can also be due to a weight change be achieved.

In the hollow boxes can also Senso order to display and / or signaling of climatic conditions and / or structural changes. Likewise, it is possible in the designed hollow box cross-sections to carry out structural engineering studies by measuring robot that pass through the hollow boxes.

The The invention will be explained using exemplary embodiments. Show it

1 the hollow box girder in standard version,

2 the box girder with sound insulation and

3 the box girder with fire protection.

In 1 a box girder is shown in standard version. It consists of a plate-shaped upper flange 1 in layer construction of two sandwich panels 1.1 . 1.2 made of solid wood, a plate-shaped bottom flange 2 in layer construction of two sandwich panels 2.1 . 2.2 made of solid wood as well as between upper strap 1 and bottom strap 2 arranged extending in the carrier longitudinal direction and upper and lower belt 1 . 2 connecting webs 3 ,

The sandwich panels of upper and lower belt 1 . 2 are constructed of board layers in the form of transverse board and board longitudinal layers.

The bridges 3 Composed of laminated timber (BS wood) with board layers 4.1 - 4-n , One jetty each 3.1 . 3 , 2 limits the hollow box carrier each outside and between these webs 3.1 . 3.2 are in carrier longitudinal direction two more webs 3.3 . 3.4 arranged.

All touching oneself or contiguous Parts are glued together by vacuum pressing using a formaldehyde-free adhesive.

The bridges 3.1 - 3.4 are parallel to each other and are arranged symmetrically with respect to the carrier cross-section. Of course it is also possible in the interest of a strength optimization that the outer webs 3.1 and 3.2 assume a non-parallel course in the carrier longitudinal direction and / or at least one between the outer webs 3.1 and 3.2 arranged bridge 3.n a non-parallel course to an outer web 3.1 assumes in the carrier longitudinal direction.

The board layers 4.1 - 4-n of the bridges 3 are glued together fiber-parallel. Again, there is a possibility that at least one layer 4.x at an angle to the fiber (non-parallel) of the follower layer 4.x + 1 is arranged.

The exemplified dimension shows the dimensioning of the proposed box carrier without to limit the invention to it. It is quite possible carrier with a width of up to 4 m (b) and a length of up to 20 m. The height (h) is variable.

In the hollow boxes 9 can be arranged sensors for displaying and / or signaling of climatic conditions and / or structural changes. The dimensioning also makes it possible that for structural engineering measuring robots, the hollow boxes 9 passed through.

2 shows a box girder with sound insulation. This is the inner layer plate 2.2 on her in the hollow box 9 facing side with an insulation layer 5 , preferably a heat-insulating and / or sound-absorbing layer has been provided. Furthermore, the lower chord 2 through openings 8th , Preferably bores and / or slots in the respective hollow box 9 on.

3 shows the box girder with fire protection optimal equipment in the form of a on the outer surface of the lower flange 2 arranged fire protection layer 6 , preferably a fire protection fabric made of expanded graphite and a wear layer 7 made of hardwood or a hardwood laminate (B1 building material).

Of course, combinations of applied or introduced layers are possible to impose strength, fire protection, sound and / or thermal insulation properties. Likewise, an embodiment sees the complete foaming of the hollow boxes 9 before or blowing out with cellulose.

Of the proposed hollow box girder made of wood combines the properties in an advantageous manner of hollow beams and of BS wood or cross laminated wood, creating an alternative to the indicated alignment exclusively to BS-wood or to Cross laminated wood.

One Another advantage is the low energy consumption in the production, because only one step in the production of the carrier necessary is.

1

upper chord

1.1

Outer layer / layer of boards

1.2

Inner layer / layer of boards

2

lower chord

2.1

Outer layer / layer of boards

2.2

Inner layer / layer of boards

3.1-3.n

Stege

4.1-4.n

Brett layers of the bridges

5

insulation layer

6

Fire protection layer

7

wearing course

8th

openings

9

girders

Claims (18)

Hollow box girder consisting of a plate-shaped upper girth ( 1 ) in layered construction of at least two sandwich panels ( 1.1 . 1.2 ) made of solid wood, a plate-shaped bottom flange ( 2 ) in layered construction of at least two sandwich panels ( 2.1 . 2.2 ) made of solid wood and between 1 ) and lower chord ( 2 ) arranged in the carrier longitudinal direction extending and upper and lower chord ( 1 . 2 ) connecting webs ( 3 ), whereby the webs ( 3 ) of softwood planks and / or glulam (BS wood) with board layers ( 4.1 - 4-n ), one jetty each ( 3.1 . 3.2 ) the hollow box carrier each limited outside and between these webs ( 3.1 . 3.2 ) at least one further bridge ( 3.n ) is arranged and adhering or abutting parts are glued together. Box girder according to claim 1, characterized in that the webs ( 3.1 - 3.n ) run parallel to one another, preferably symmetrically with respect to the carrier cross-section. A box girder according to claim 1, characterized in that the outer webs ( 3.1 and ( 3.2 ) assume a non-parallel course in the carrier longitudinal direction. A box girder according to claim 1 or 3, characterized in that at least one between the outer webs ( 3.1 ) and ( 3.2 ) arranged web ( 3.n ) a non-parallel course to an outer web ( 3.1 ) occupies in the carrier longitudinal direction. Box girder according to one of claims 1 to 4, characterized in that of the board layers ( 4.1 - 4-n ) of the webs ( 3 ) at least one layer ( 4.x ) at an angle to the fiber (nonparallel) of the subsequent layer ( 4.x + 1 ) is arranged. A box girder according to any one of claims 1 to 5, characterized in that the sandwich panels of upper and / or lower chord ( 1 . 2 ) consist of board layers. Box girder according to claim 6, characterized in that the board layers Board transverse and longitudinal boards are constructed. A box girder according to any one of claims 1 to 7, characterized in that at least one layer plate ( 1.2 ) or ( 2.2 ) on her in the hollow box ( 9 ) facing side an insulation layer ( 5 ), preferably a heat-insulating and / or sound-absorbing layer. A box girder according to any one of claims 1 to 8, characterized in that the box or boxes ( 9 ) are filled with a foam, blown out or the mechanical properties improving layers or fabric layers are arranged on the hollow box inner walls. Box girder according to one of claims 1 to 9, characterized in that on the outer surface of at least one belt ( 1 . 2 ), preferably the lower flange ( 2 ) a sound or fire protection layer ( 6 ) is arranged. A box girder according to claim 10, characterized in that the fire protection layer ( 6 ) is a fire-resistant fabric, preferably expandable graphite. Box girder according to one of claims 1 to 11, characterized in that on the outer surface of at least one belt ( 1 . 2 ) preferably of the lower flange ( 2 ) and preferably on the outer surface of the fire protection layer ( 6 ) a wear layer ( 7 ) is arranged. Box girder according to claim 12, characterized in that the wear layer ( 7 ) consists of hardwood or a hardwood laminate. Box girder according to one of claims 1 to 13, characterized in that at least one belt ( 1 . 2 ), preferably the lower flange ( 2 ) as well as on the straps ( 1 . 2 ) arranged layers through openings ( 8th ) in the respective hollow boxes ( 9 ) exhibit. Box girder according to one of claims 1 to 14, characterized in that the bonding is more touching or more abutting Parts by vacuum pressing using a formaldehyde-free Glue is done. Box girder according to one of claims 1 to 15, characterized in that hollow box carrier with Dimensions up to 4 m width (b) and up to 20 m length in one Step are made. Box girder according to one of claims 1 to 16, characterized in that in the hollow boxes ( 9 ) Sensors for indicating and / or signaling of climatic conditions and / or structural changes are arranged. Box girder according to one of the claims 1 to 17, characterized in that the webs ( 3 ) are formed voltage-optimized, and in particular have a substantially rectangular or conical cross-section, or are formed as double-T-webs.